Esterified cellulose ethers having a specific substituent distribution

US9320799B2 · kind B2 · utility

Assignee

• DOW GLOBAL TECHNOLOGIES LLC · US

Inventors

• Robert L. Schmitt · Stuart, US
• Robert L. Sammler · Midland, US
• Meinolf Brackhagen · Walsrode, DE
• Oliver Petermann · Hamburg, DE
• Roland Adden · Bad Fallingbostel, DE
• Nicholas S. Grasman · Midland, US
• Steven J. Guillaudeu · Midland, US

Key dates

• Filing date: Oct 24, 2012
• Grant date: Apr 26, 2016
• Expiry date: Oct 24, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08B13/00
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

An esterified cellulose ether comprises (i) aliphatic monovalent acyl groups or (ii) groups of the formula —C(O)—R—COOA wherein R is a divalent aliphatic or aromatic hydrocarbon group and A is hydrogen or a cation or (iii) a combination of aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOA, wherein the cellulose ether has anhydroglucose units joined by 1-4 linkages and has methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl as substituents such that the esterified cellulose ether has an MS (hydroxyalkyl) of 0.05 to 1.00, and hydroxyl groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS(hydroxyalkyl)] is 0.36 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 3-positions of the anhydroglucose unit are substituted with a methyl group and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 6-positions of the anhydroglucose unit are substituted with a methyl group. The esterified cellulose ether is useful as an excipient for poorly water-soluble drugs.